Hard Water Species
Lake Malawi (mbuna, peacocks, haps): pH 7.8-8.6, dKH 10-15, dGH 10-15. Lake Tanganyika (frontosa, multies): same or slightly higher.
Crushed coral, aragonite sand, or buffer salts maintain these parameters.
Soft Water Species
Discus, angelfish, apistogramma, ram: pH 5.5-6.8, dKH 1-5, dGH 3-8. Amazonian blackwater origin.
Driftwood, Indian almond leaves, and peat moss lower pH and hardness naturally.
Neutral Hardness
Convict, firemouth, jack dempsey, flowerhorn tolerate pH 7.0-8.0 and moderate hardness. Flexible for mixed keeping.
These are the best beginner cichlids for tap water without adjustment.
RO vs Tap Water
RO water lets you customize parameters for any species. Essential for discus and apisto breeders.
Tap water works for hardy species if parameters naturally fit. Test your tap source first.